NUCLEAR ALTERATIONS IN HEPATOCYTES OF ARCTIC CHAR SALVELINUS-ALPINUS FROM ACIDIC HIGH ALPINE LAKES

The hepatocyte morphology of Arctic char Salvelinus alpinus from 2 aci dic, a circumneutral and 3 alkaline lakes in the Austrian Alps (Tyrol and Styria) was compared with respect to nuclear alterations and relat ed to environmental parameters. Extensive glycogen storage of hepatocy te nuclei could regularly be found in Arctic char from the 2 acidic hi gh mountain lakes. In contrast, in Arctic char from the circumneutral lake (slightly acidic during winter), nuclear glycogen storage could o nly be documented in a few specimens. In alkaline lakes, however, nucl ear glycogen deposition was absent in 64 out of 65 specimens. Addition al nuclear pathology in char of the most acidic lake was evident from a reorganization of nucleolar components. The number of nuclei involve d in glycogen storage showed a distinct seasonal pattern which correla ted with the intensity of feeding, but not with the seasonality of oth er environmental parameters (trace metals, temperature, pH).